Removal of Proteins and Its Effect on Molecular Structure and Properties of Natural Rubber

Engineering and Technology For Sustainable Development - Tập 32 Số 2 - Trang 8-15 - 2022
Thi Thuong Nghiem1, Trung Nghia Phan1, Seiichi Kawahara2
1School of Chemical Engineering, Hanoi University of Science and Technology, Hanoi, Vietnam
2Faculty of Engineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan

Tóm tắt

Removal of protein from natural rubber was carried out via deproteinization of natural rubber in the latex stage. Then, its effect on the molecular structure and properties of natural rubber was investigated. Urea, SDS, and acetone were used as denaturing agent, a surfactant, and a polar solvent in the deproteinization, respectively. Various deproteinized natural rubbers were obtained after one, two, and three times of centrifugation with and without acetone, namely DPNR1, DPNR2, DPNR3, DPNR1-A, DPNR2-A, and DPNR3-A. It was found that the total protein content significantly decreased as increasing the number of centrifugations; however, the total fatty acid contents showed a slight decrease. Structural characteristics analyzed by nuclear magnetic resonance spectroscopy indicated no changes in the chemical structure of natural rubber after deproteinization. However, the removal of proteins significantly enhanced the resolution of the NMR signals. Gel content and tensile properties of natural rubber showed a decrease in the removal of proteins, which was associated with the decrease in the number of the inherent branching points formed in natural rubber.

Từ khóa

#deproteinized natural rubber #proteins #NMR signal #tensile property

Tài liệu tham khảo

N.T. Thuong, Y. Oraphin, P.T. Nghia, S. Kawahara.

Effect of naturally occurring crosslinking junctions on

green strength of natural rubber, Polym. Adv.

Technol., vol. 28, pp. 303–311, 2016.

https://doi.org/10.1002/pat.3887

E.C. Gregg, J.H. Macey, The relationship of properties

of synthetic poly(isoprene) and natural rubber in the

factory. The effect of non rubber constituents of

natural rubber, Rubber. Chem. Technol, vol. 46, pp.

–66, 1973.

https://doi.org/10.5254/1.3545022

Y. Zhou, K. Kosugi, Y. Yamamoto, S. Kawahara. Effect

of non rubber components on the mechanical properties

of natural rubber, Polym. Adv. Technol, vol. 28, pp.

–165, 2017.

https://doi.org/10.1002/pat.3870

S. Amnuaypornsri, L. Tarachiwin, J.T. Sakdapipanich,

Character of long chain branching in highly purified

natural rubber. J. Appl. Polym. Sci. vol. 115, pp. 3645-

, 2010.

https://doi.org/10.1002/app.31419

Y. Tanaka, Structural characterization of natural

polyisoprenes: solve the mystery of natural rubber

based on structural study, Rubber Chem Technol,

vol.74, pp. 355-375, 2001.

https://doi.org/10.5254/1.3547643

S. Kawahara, Y. Isono, J.T. Sakdapipanich, Y. Tanaka,

E. Aik-Hwee. Effect of gel on the green strength of

natural rubber, Rubber. Chem. Technol, vol 75, 739–

, 2002.

https://doi.org/10.5254/1.3544999

O. Chaikumpollert, Y. Yamamoto, K. Suchiva, P.T.

Nghia, S. Kawahara, Preparation and characterization

of protein-free natural rubber, Polym. Adv.Technol.,

vol. 23, pp. 825–828, 2011.

https://doi.org/10.1002/pat.1965

S. Kawahara, W. Klinklai, H. Kuroda, Y. Isono,

Removal of proteins from natural rubber with urea,

Polym Adv Technol. Vol 15, pp. 181-184, 2004.

https://doi.org/10.1002/pat.465

Rubber Research Institute of Malaysia, Determination

of nitrogen, SMR Bull. No.1, Part B.7, Now. 1973.

S Toki, J Che, L Rong, BS Hsiao, S Amnuaypornsri,

A Nimpaiboon, J Sakdapipanic, Entanglements and

networks to strain-induced crystallization and stress–

strain relations in natural rubber and synthetic

polyisoprene at various temperatures,

Macromolecules. Vol 46, pp. 5238-5248, 2013.

https://doi.org/10.1021/ma400504k

Thông tin
Thông tin xuất bản

Engineering and Technology For Sustainable Development

Tập 32 Số 2

8-15

Thông tin tác giả